Double apron drawing arrangement for spinning machines



2,942,307 DOUBLE APRON DRAWING ARRANGEMENT FOR SPINNING MACHINES Filed June 25, 1958 June 28, 1960 A. SCHILTKNECHT ETAL 2 Sheets-Sheet 1 IN VEN TORS. flDQLr-SCHILTKNECHI FE/PNA ND Cousuv.

ATTORNEY.

June 28, 1960 A. SCHILTKNECHT ETAL DOUBLE APRON DRAWING ARRANGEMENT FOR SPINNING MACHINES Filed June 25, 1958 Fig 6 2 Sheets-Sheet 2 INVENTORS. flDOLFScH/LTKNECHZ' HEP/VA ND COUS/N.

ATTOENEX nitedStates Patent DOUBLE APRON DRAWING ARRANGEMENT FOR SFINNIN G MACHINES Adolf Schiltknecht, Winterthur, and Fernand Cousin, Chippls, Switzerland, assignors to Job. Jacob Rieter & Co. Ltd., Winterthur, Switzerland, a corporation of Switzerland Filed June 25, 1958, Ser. No. 744,370

Claims priority, application Switzerland June 29, 1957 Claims. (Cl. 19-131) The present invention relates to a double apron drawing arrangement for spinning machines and more particularly to adjustable means for guiding and reversing the lower apron of such arrangements.

In conventional double apron drawing arrangemen for spinning machines the retainment of the sliver is adjusted by changing the pressure acting on the, sliver or by tribution of the pressure is most nearly obtained, if the curvature of thebridge" or bar acting on, the aprons can be continuously, i.e., not stepwisely 'adjusted and retained in the optimal condition. Such adjustment takes time. Interchangeable reversing bars having .difierent profiles have been used to facilitate the adjustment. Keeping an adequate supply of these bars is costly.

The object of the present invention is to provide a're- 'versing bar arrangement forthe lower apron of double apron drafting arrangements for spinning machines in which only one bar can satisfy a great number of diiferent drawing conditions. The bar according to the invention has a plurality of differently shaped surface portions which are selectively engageable by the lower apron. The

bar and its support-are provided with complementary "means affording fixing of the bar in different positions so that a selected one of its surface portions, engages and guides the apron.

For machines in which bearing notches are already present in the drawing roller supports which notches are not coaxial'with the reversal bars, the invention provides adaptors individually having a portion resting in one of the existing'notches. The adaptors have means located symmetrically with respect to the longitudinal axis of the reversal bar and adapted to engage complementary means associated with the reversal bar. structure permits connection of 'the reversal bar and of the adaptor in different relative angular positions. I

The novel features which are considered characteristic of the inventionare set forth with particularity in 'the appended claims. The ;ir i ven tion itself, however, and additional objectlslg nd advantages thereof will best be understood from''the following description of embodiments thereof when. read. in connection 'with theaccompanying drawing, in which:

Fig. 1 is a diagrammatic side view of a double apron drawing arrangement including an adjustable bar according to the invention for guiding the lower apron.

Fig. 2 shows a portion of Fig. lwith the adjustable bar in a different position.

Fig. 3 shows a portion of Fig. 1 with the adjustable bar in a third position.

Fig. 4 shows a portion of Fig. 1 bar in a fourth position. v

Fig. 5' is a diagrammatic side view of a guide bar according to the invention.

Fig. 6 is a diagrammatic cross sectional view of a modified arrangement for adjustably supporting a guide bar.

Fig. 7 is a diagrammatic side view of the arrangement shown in Fig. 6 with the drawing roller support removed.

Fig. 8 is an end view-of a guide bar and of an intermediate element according to the invention for angular-1y adjustably supporting the guide bar.

Fig. 9 is a diagrammatic part sectional view of the with the adjustable device shown in Fig. 8, the section being taken along line IXIX in Fig. 8, a roller support being added.

Fig. '10 is a perspective end view of the guide bar and intermediate element shown in Fig. 8.

Referring more particulraly to Fig. l of the drawing, numerals 2, 3, 4 designate drawing roller supports mounted and secured on a roller stand in the conventional manner. Drawing rollers 8, 9 and 10 rotatably rest in suitable recesses 5, 6 and 7 of the supports 2, 3, 4, respectively. Loaded top rollers 11, 12 and 13, which may be guided at their ends or in their middle portions, rest on the drawing rollers 8, 9 and 10; The roller 12 which is between the rollers 11 and 13 carries a conventional guide cradle 147which guides a top apron 15 laid around the cradle so that the top apron moves along a lower apron 16 to the nip of the delivery rollers 8 and 11. The lower apron 16 is tensioned in known manner by conventional tensioning devices, not shown, which are located below the run of the lower apron 16 which run is adjacentto the upper apron. The lower apron 16 is first guided by and subsequently turned around a reversing bridge or bar 17 having a generally prismatic configuration, the individual surfaces 40, 41, 42 of the bar 17 having different configurations. The surface 40 is plane, the surface 41 uniformly convexly curved and the surface 42 has a protuberance18 which rests in a complementary notch 19 of the support 2. The thickness of the latter is preferably twice the longitudinal extension of the protuberance 18 so that the protuberances of two axially aligned bores can be received in the same notch. The bar 17 can easily be lifted out of the notch 19, turned on its longitudinal axis and reinserted in thenotc-h for changing the curvature on which the lower apron is guided to comply with different drawing requirements. Figs. 2 and 3 i1lustrate two different operating conditions of the bar 17 which can be obtained by clockwisely turning the bar on its longitudinal axis. 7

By turning the bar from the position shown in Fig. 2 in a plane which is parallel'to the drafting field and on an axis which is normal to the longitudinal axis of the bar, as indicated in Fig. 5, an additional position, shown in Fig. 4,' canbe obtained and two further'positions can be obtained by turning the bar on its longitudinal axis from the position shown in Fig. 4. With a generally prismatic bar 17 six different operating positions can be obtained. Experience hasshown that six different operating positions are generally sufiicient to cope with anyd'rawing requirement. If desired, the bar may be provided with a quadratic cross section to increase the number of surfaces to four. The bar can be provided with a polygonal cross section having more than four corners to further increase the number of different surfaces from which a desired surface can be selected. The bar may also be so modified that it has only two difierent operating surfaces.

Figs. 6 and 7 illustrate a modified embodiment of the Patented June 28, 19 0 invention. A holder 20 is mounted by means of screws on the drawing roller support or bearing 2. The central portion of the holder 20 is provided with a vertical slot 21. slidably receivinga rail 22, the top of which forms a clamping member 23. The member 23 is provided with a bore 24, continuing in. a slot 25'. In the bore 24' a short pin 26' is received which pin extends axially from an end of a reversing bridge or bar 17. The diameter of the pin 26 is so that the pin must be forced into the bore. 24 whereby the prongs formed on the member 23' by the bore 24 and the slot 25 are slightly pressed apart so that the, pin 26 is retained in any desired angular position by a clamping efieot in contradistinction. to the arrangement' shown in Figs. 1 to in which the bar 17 can be held only in three ditferent angular positions. The arrow 43 in Fig. 7 indicates the rotatability of the bar 17 in opposits directions. By inserting shims 27' of suitable thickness between the holder 20. and the clamping head 23 the position of the bar 17" can be vertically adjusted as indicated. by arrows 44 in Fig. 7. The shims 27 are held in place by the end of the bar 17.

Figs. 8, 9 and illustrate a further embodiment of the invention. The end of the bridge member or bar 28 is provided with a short axial. bore 29. Three bores 31 extend from the bottom 30 of the cavity formed by the bore 29 into the bar 28. The bores 31 are arrangedon a circle whose center is in the longitudinal axis of the bore 29. The bores 31 are angularly spaced by I20 The bar 28 is supported by an intermediate piece 32 having a cylindrical portion 34 fitting into the bore 29 and a protuberance 36 extending in axial direction from the cylindrical portion 34' and into a recess 35' in the support 2 which recess is nonsymmetric with respect to the longitudinal axis of the bar 28. A rodlike protuberance 37 extends from the portion 34 in a direction which is opposite .to the extension of the protuberance 36. For changing the angular position of the bar 28 the bar with the intermediate piece 32' is taken out of the recess 35 whereupon the intermediate piece 32 is pulled out of the bar 28 and rotated for insertion of the rodlike protuberance 37 in a desired one of the bores: 31. After this has been done. the assembly is again inserted in the recess 35 of the drawing roller support. The modification illustrated in Figs. 8 to 10 is particularly suitable inconnecti'on with machines which already have notches. or recesses which are not suitable for using the embodiments of the invention shown in Figs. 1 to 7. The modification shown in Figs. 8 to 1.0 is also suitable for adapting machines which initially did'not have rotatable reversingbars. to the use of adjustable. reversing bars according to. the invention.

What is claimed is:

l. Ina double apron drawing arrangement for spinning machines, a lower apron in the form of an endless belt having an upper run supporting the textile fibres, a guide bar placed beneath said upper run and. having a plurality of reversing edges and a differently shaped guidesurface portion extending from. each of said reversing edgesfor guiding a substantial portion of said upper run, and support means. for said guide bar, said guide bar and said support means including cooperating means for selectively placing said guide bar in a position in which a selected one of said guide surface portions is adjacent to. and

guides a substantial part of. said upper run according to the shapeoffthe respective, guide surface.

2. Ina double apron drawing. arrangement as defined m-claim l andwhereinsaid bar is rotatable on its longitudinal axis and said surface portions are parallel to the longitudinal axis of the bar.

3. In a double apron drawing arrangement as defined in claim 1 and wherein said bar rests on said support means and is liftable therefrom for swinging said bar in a plane parallel to the drafting. field and. on an axis which is normal. to the longitudinal axis of the bar for changing the operating positions of the individual surface portions. 7

4. In a doublev apron drawing arrangement. according to claim. 2. and wherein: said cooperating means include complementary holding means engageable one by the other for holding said barin selected angular positions.

5. In a double apron drawing arrangement according to claim 4 andwherein said complementary holding means are provided with. plane surfaces parallel to the longitudinal axis of the bar and placed at an angle to each other for stepwisely changing the angular position of said bar.

6'. In a double apron drawing arrangement according to claim 4 and wherein. said holding means provided on said bar are in the form of. equilateral prisms and said holding means provided on said support means are in the form of triangular notches individually receiving said prisms, said bar having. the. general. configuration of a prism whose longitudinal. surfaces are individually parallel to the surfaces. of the holding means provided'on said bar.

7'. In a double apron drawing arrangement according to claim 4 and wherein. said. complementary holding means are provided with. cylindrical surfaces coaxial of the longitudinal axis of. the bar andfrictionally engaging one another for continuously changing the angular position' of said bar.

8. Ina. double apron drawing arrangement according to claim 7 and wherein the holding means on said bar are cylindrical. and. coaxial of said bar and the holding means on said support means are in the form. of clamps clamping the cylindrical holding means on said bar in a direction normal to the longitudinal axis of the bar.

9. In a double apron drawing arrangement as defined in. claim 1 and. wherein said cooperating means include means for changing the position of said bar relatively to the drafting. field.

10.. In a. double apron drawing: arrangement. for. spinning. machines, a lower apron. in the form of an endless belt having an upper run supporting thetextilefibres, a guide bar placed beneath said upper run and having a plurality of reversing edges and a differently shaped guide surface portion. extending from each of said' reversing edges for guiding a substantial portion of said upper. run, support means, and an. element having apart resting on said. support means and having: a portion engageable-with said guide. bar for supporting. said guide bar, said guide bar having a plurality of means individually complementary to said portion on. said element for individually engaging. said. last mentioned portion, said complementary means being arranged symmetrically around the longitudinal axisof said guide bar for changing the relative angular position ofv saidguide-bar and saidelement.

References Cited inthefile ofithisv patent UNITED STATES PATENTS 2,703,440 Poovey' Mar. 8, 1956 FOREIGN PATENTS 662,001 Germany July 2, I938 

